<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <ul class="cl">
        <li>132</li>
        <li>132</li>
        <li>132</li>
        <li>132</li>
        <li>132</li>
        <li>132</li>
        <li>132</li>
        <li>132</li>
        <li>132</li>
        <li>132</li>
    </ul>
    <script>
         var oli=document.getElementsByTagName('li'),
            oul=document.getElementsByClassName('cl')[0];
            console.log(oul);
            console.log(oli);
            
            oul.addEventListener('click',function(e){
                var tar=e.target;
                console.log(Array.prototype.indexOf.call(oli,tar));
            })
    </script>
</body>
</html>